Lasers have found a number of applications in medical procedures. Using suitably focused and powerful laser beams, tissues can be excised, ablated or cut with fine control and with reduced bleeding. Example treatments are excision and vaporisation of benign and cancerous growths and fibromas, and aesthetic treatments. Conventionally, a CO2 laser is used as the source of the beam producing light at a wavelength of 10.6 μm. Because this wavelength is not suitable for transmission through conventional optical fibres, where it would be absorbed by the silica, it is known to use either hollow flexible waveguides, or internally reflective articulated arms, to direct the beam to the site of operation.